The coil on the table appeared to be a snake - tan and brown with black specks and a spade-shaped head. It did not look alive and it did not look dead.
...He reached down and partially uncoiled the snake, then squeezed its middle. A small hatch popped open, giving a glimpse of gleaming steel ribs and wires.

Readers may like these sfnal predecessors to this idea; the mining worm robot from Love Among the Robots (1946) by Emmett McDowell and the mechanical cobra from Lord of Light (1967) by Roger Zelazny.